/*!
    localForage -- Offline Storage, Improved
    Version 1.9.0
    https://localforage.github.io/localForage
    (c) 2013-2017 Mozilla, Apache License 2.0
*/
(function (f) {
    var g;
    if (typeof window !== "undefined") {
        g = window
    } else if (typeof global !== "undefined") {
        g = global
    } else if (typeof self !== "undefined") {
        g = self
    } else {
        g = this
    }
    g.localforage = f()
}
)(function () {
    var define, module, exports;
    return (function e(t, n, r) {
        function s(o, u) {
            if (!n[o]) {
                if (!t[o]) {
                    var a = typeof require == "function" && require;
                    if (!u && a)
                        return a(o, !0);
                    if (i)
                        return i(o, !0);
                    var f = new Error("Cannot find module '" + o + "'");
                    throw (f.code = "MODULE_NOT_FOUND",
                        f)
                }
                var l = n[o] = {
                    exports: {}
                };
                t[o][0].call(l.exports, function (e) {
                    var n = t[o][1][e];
                    return s(n ? n : e)
                }, l, l.exports, e, t, n, r)
            }
            return n[o].exports
        }
        var i = typeof require == "function" && require;
        for (var o = 0; o < r.length; o++)
            s(r[o]);
        return s
    }
    )({
        1: [function (_dereq_, module, exports) {
            (function (global) {
                'use strict';
                var Mutation = global.MutationObserver || global.WebKitMutationObserver;

                var scheduleDrain;

                {
                    if (Mutation) {
                        var called = 0;
                        var observer = new Mutation(nextTick);
                        var element = global.document.createTextNode('');
                        observer.observe(element, {
                            characterData: true
                        });
                        scheduleDrain = function () {
                            element.data = (called = ++called % 2);
                        }
                            ;
                    } else if (!global.setImmediate && typeof global.MessageChannel !== 'undefined') {
                        var channel = new global.MessageChannel();
                        channel.port1.onmessage = nextTick;
                        scheduleDrain = function () {
                            channel.port2.postMessage(0);
                        }
                            ;
                    } else if ('document' in global && 'onreadystatechange' in global.document.createElement('script')) {
                        scheduleDrain = function () {

                            // Create a <script> element; its readystatechange event will be fired asynchronously once it is inserted
                            // into the document. Do so, thus queuing up the task. Remember to clean up once it's been called.
                            var scriptEl = global.document.createElement('script');
                            scriptEl.onreadystatechange = function () {
                                nextTick();

                                scriptEl.onreadystatechange = null;
                                scriptEl.parentNode.removeChild(scriptEl);
                                scriptEl = null;
                            }
                                ;
                            global.document.documentElement.appendChild(scriptEl);
                        }
                            ;
                    } else {
                        scheduleDrain = function () {
                            setTimeout(nextTick, 0);
                        }
                            ;
                    }
                }

                var draining;
                var queue = [];
                //named nextTick for less confusing stack traces
                function nextTick() {
                    draining = true;
                    var i, oldQueue;
                    var len = queue.length;
                    while (len) {
                        oldQueue = queue;
                        queue = [];
                        i = -1;
                        while (++i < len) {
                            oldQueue[i]();
                        }
                        len = queue.length;
                    }
                    draining = false;
                }

                module.exports = immediate;
                function immediate(task) {
                    if (queue.push(task) === 1 && !draining) {
                        scheduleDrain();
                    }
                }

            }
            ).call(this, typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
        }
            , {}],
        2: [function (_dereq_, module, exports) {
            'use strict';
            var immediate = _dereq_(1);

            /* istanbul ignore next */
            function INTERNAL() { }

            var handlers = {};

            var REJECTED = ['REJECTED'];
            var FULFILLED = ['FULFILLED'];
            var PENDING = ['PENDING'];

            module.exports = Promise;

            function Promise(resolver) {
                if (typeof resolver !== 'function') {
                    throw new TypeError('resolver must be a function');
                }
                this.state = PENDING;
                this.queue = [];
                this.outcome = void 0;
                if (resolver !== INTERNAL) {
                    safelyResolveThenable(this, resolver);
                }
            }

            Promise.prototype["catch"] = function (onRejected) {
                return this.then(null, onRejected);
            }
                ;
            Promise.prototype.then = function (onFulfilled, onRejected) {
                if (typeof onFulfilled !== 'function' && this.state === FULFILLED || typeof onRejected !== 'function' && this.state === REJECTED) {
                    return this;
                }
                var promise = new this.constructor(INTERNAL);
                if (this.state !== PENDING) {
                    var resolver = this.state === FULFILLED ? onFulfilled : onRejected;
                    unwrap(promise, resolver, this.outcome);
                } else {
                    this.queue.push(new QueueItem(promise, onFulfilled, onRejected));
                }

                return promise;
            }
                ;
            function QueueItem(promise, onFulfilled, onRejected) {
                this.promise = promise;
                if (typeof onFulfilled === 'function') {
                    this.onFulfilled = onFulfilled;
                    this.callFulfilled = this.otherCallFulfilled;
                }
                if (typeof onRejected === 'function') {
                    this.onRejected = onRejected;
                    this.callRejected = this.otherCallRejected;
                }
            }
            QueueItem.prototype.callFulfilled = function (value) {
                handlers.resolve(this.promise, value);
            }
                ;
            QueueItem.prototype.otherCallFulfilled = function (value) {
                unwrap(this.promise, this.onFulfilled, value);
            }
                ;
            QueueItem.prototype.callRejected = function (value) {
                handlers.reject(this.promise, value);
            }
                ;
            QueueItem.prototype.otherCallRejected = function (value) {
                unwrap(this.promise, this.onRejected, value);
            }
                ;

            function unwrap(promise, func, value) {
                immediate(function () {
                    var returnValue;
                    try {
                        returnValue = func(value);
                    } catch (e) {
                        return handlers.reject(promise, e);
                    }
                    if (returnValue === promise) {
                        handlers.reject(promise, new TypeError('Cannot resolve promise with itself'));
                    } else {
                        handlers.resolve(promise, returnValue);
                    }
                });
            }

            handlers.resolve = function (self, value) {
                var result = tryCatch(getThen, value);
                if (result.status === 'error') {
                    return handlers.reject(self, result.value);
                }
                var thenable = result.value;

                if (thenable) {
                    safelyResolveThenable(self, thenable);
                } else {
                    self.state = FULFILLED;
                    self.outcome = value;
                    var i = -1;
                    var len = self.queue.length;
                    while (++i < len) {
                        self.queue[i].callFulfilled(value);
                    }
                }
                return self;
            }
                ;
            handlers.reject = function (self, error) {
                self.state = REJECTED;
                self.outcome = error;
                var i = -1;
                var len = self.queue.length;
                while (++i < len) {
                    self.queue[i].callRejected(error);
                }
                return self;
            }
                ;

            function getThen(obj) {
                // Make sure we only access the accessor once as required by the spec
                var then = obj && obj.then;
                if (obj && (typeof obj === 'object' || typeof obj === 'function') && typeof then === 'function') {
                    return function appyThen() {
                        then.apply(obj, arguments);
                    }
                        ;
                }
            }

            function safelyResolveThenable(self, thenable) {
                // Either fulfill, reject or reject with error
                var called = false;
                function onError(value) {
                    if (called) {
                        return;
                    }
                    called = true;
                    handlers.reject(self, value);
                }

                function onSuccess(value) {
                    if (called) {
                        return;
                    }
                    called = true;
                    handlers.resolve(self, value);
                }

                function tryToUnwrap() {
                    thenable(onSuccess, onError);
                }

                var result = tryCatch(tryToUnwrap);
                if (result.status === 'error') {
                    onError(result.value);
                }
            }

            function tryCatch(func, value) {
                var out = {};
                try {
                    out.value = func(value);
                    out.status = 'success';
                } catch (e) {
                    out.status = 'error';
                    out.value = e;
                }
                return out;
            }

            Promise.resolve = resolve;
            function resolve(value) {
                if (value instanceof this) {
                    return value;
                }
                return handlers.resolve(new this(INTERNAL), value);
            }

            Promise.reject = reject;
            function reject(reason) {
                var promise = new this(INTERNAL);
                return handlers.reject(promise, reason);
            }

            Promise.all = all;
            function all(iterable) {
                var self = this;
                if (Object.prototype.toString.call(iterable) !== '[object Array]') {
                    return this.reject(new TypeError('must be an array'));
                }

                var len = iterable.length;
                var called = false;
                if (!len) {
                    return this.resolve([]);
                }

                var values = new Array(len);
                var resolved = 0;
                var i = -1;
                var promise = new this(INTERNAL);

                while (++i < len) {
                    allResolver(iterable[i], i);
                }
                return promise;
                function allResolver(value, i) {
                    self.resolve(value).then(resolveFromAll, function (error) {
                        if (!called) {
                            called = true;
                            handlers.reject(promise, error);
                        }
                    });
                    function resolveFromAll(outValue) {
                        values[i] = outValue;
                        if (++resolved === len && !called) {
                            called = true;
                            handlers.resolve(promise, values);
                        }
                    }
                }
            }

            Promise.race = race;
            function race(iterable) {
                var self = this;
                if (Object.prototype.toString.call(iterable) !== '[object Array]') {
                    return this.reject(new TypeError('must be an array'));
                }

                var len = iterable.length;
                var called = false;
                if (!len) {
                    return this.resolve([]);
                }

                var i = -1;
                var promise = new this(INTERNAL);

                while (++i < len) {
                    resolver(iterable[i]);
                }
                return promise;
                function resolver(value) {
                    self.resolve(value).then(function (response) {
                        if (!called) {
                            called = true;
                            handlers.resolve(promise, response);
                        }
                    }, function (error) {
                        if (!called) {
                            called = true;
                            handlers.reject(promise, error);
                        }
                    });
                }
            }

        }
            , {
            "1": 1
        }],
        3: [function (_dereq_, module, exports) {
            (function (global) {
                'use strict';
                if (typeof global.Promise !== 'function') {
                    global.Promise = _dereq_(2);
                }

            }
            ).call(this, typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
        }
            , {
            "2": 2
        }],
        4: [function (_dereq_, module, exports) {
            'use strict';

            var _typeof = typeof Symbol === "function" && typeof Symbol.iterator === "symbol" ? function (obj) {
                return typeof obj;
            }
                : function (obj) {
                    return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj;
                }
                ;

            function _classCallCheck(instance, Constructor) {
                if (!(instance instanceof Constructor)) {
                    throw new TypeError("Cannot call a class as a function");
                }
            }

            function getIDB() {
                /* global indexedDB,webkitIndexedDB,mozIndexedDB,OIndexedDB,msIndexedDB */
                try {
                    if (typeof indexedDB !== 'undefined') {
                        return indexedDB;
                    }
                    if (typeof webkitIndexedDB !== 'undefined') {
                        return webkitIndexedDB;
                    }
                    if (typeof mozIndexedDB !== 'undefined') {
                        return mozIndexedDB;
                    }
                    if (typeof OIndexedDB !== 'undefined') {
                        return OIndexedDB;
                    }
                    if (typeof msIndexedDB !== 'undefined') {
                        return msIndexedDB;
                    }
                } catch (e) {
                    return;
                }
            }

            var idb = getIDB();

            function isIndexedDBValid() {
                try {
                    // Initialize IndexedDB; fall back to vendor-prefixed versions
                    // if needed.
                    if (!idb || !idb.open) {
                        return false;
                    }
                    // We mimic PouchDB here;
                    //
                    // We test for openDatabase because IE Mobile identifies itself
                    // as Safari. Oh the lulz...
                    var isSafari = typeof openDatabase !== 'undefined' && /(Safari|iPhone|iPad|iPod)/.test(navigator.userAgent) && !/Chrome/.test(navigator.userAgent) && !/BlackBerry/.test(navigator.platform);

                    var hasFetch = typeof fetch === 'function' && fetch.toString().indexOf('[native code') !== -1;

                    // Safari <10.1 does not meet our requirements for IDB support
                    // (see: https://github.com/pouchdb/pouchdb/issues/5572).
                    // Safari 10.1 shipped with fetch, we can use that to detect it.
                    // Note: this creates issues with `window.fetch` polyfills and
                    // overrides; see:
                    // https://github.com/localForage/localForage/issues/856
                    return (!isSafari || hasFetch) && typeof indexedDB !== 'undefined' && // some outdated implementations of IDB that appear on Samsung
                        // and HTC Android devices <4.4 are missing IDBKeyRange
                        // See: https://github.com/mozilla/localForage/issues/128
                        // See: https://github.com/mozilla/localForage/issues/272
                        typeof IDBKeyRange !== 'undefined';
                } catch (e) {
                    return false;
                }
            }

            // Abstracts constructing a Blob object, so it also works in older
            // browsers that don't support the native Blob constructor. (i.e.
            // old QtWebKit versions, at least).
            // Abstracts constructing a Blob object, so it also works in older
            // browsers that don't support the native Blob constructor. (i.e.
            // old QtWebKit versions, at least).
            function createBlob(parts, properties) {
                /* global BlobBuilder,MSBlobBuilder,MozBlobBuilder,WebKitBlobBuilder */
                parts = parts || [];
                properties = properties || {};
                try {
                    return new Blob(parts, properties);
                } catch (e) {
                    if (e.name !== 'TypeError') {
                        throw e;
                    }
                    var Builder = typeof BlobBuilder !== 'undefined' ? BlobBuilder : typeof MSBlobBuilder !== 'undefined' ? MSBlobBuilder : typeof MozBlobBuilder !== 'undefined' ? MozBlobBuilder : WebKitBlobBuilder;
                    var builder = new Builder();
                    for (var i = 0; i < parts.length; i += 1) {
                        builder.append(parts[i]);
                    }
                    return builder.getBlob(properties.type);
                }
            }

            // This is CommonJS because lie is an external dependency, so Rollup
            // can just ignore it.
            if (typeof Promise === 'undefined') {
                // In the "nopromises" build this will just throw if you don't have
                // a global promise object, but it would throw anyway later.
                _dereq_(3);
            }
            var Promise$1 = Promise;

            function executeCallback(promise, callback) {
                if (callback) {
                    promise.then(function (result) {
                        callback(null, result);
                    }, function (error) {
                        callback(error);
                    });
                }
            }

            function executeTwoCallbacks(promise, callback, errorCallback) {
                if (typeof callback === 'function') {
                    promise.then(callback);
                }

                if (typeof errorCallback === 'function') {
                    promise["catch"](errorCallback);
                }
            }

            function normalizeKey(key) {
                // Cast the key to a string, as that's all we can set as a key.
                if (typeof key !== 'string') {
                    console.warn(key + ' used as a key, but it is not a string.');
                    key = String(key);
                }

                return key;
            }

            function getCallback() {
                if (arguments.length && typeof arguments[arguments.length - 1] === 'function') {
                    return arguments[arguments.length - 1];
                }
            }

            // Some code originally from async_storage.js in
            // [Gaia](https://github.com/mozilla-b2g/gaia).

            var DETECT_BLOB_SUPPORT_STORE = 'local-forage-detect-blob-support';
            var supportsBlobs = void 0;
            var dbContexts = {};
            var toString = Object.prototype.toString;

            // Transaction Modes
            var READ_ONLY = 'readonly';
            var READ_WRITE = 'readwrite';

            // Transform a binary string to an array buffer, because otherwise
            // weird stuff happens when you try to work with the binary string directly.
            // It is known.
            // From http://stackoverflow.com/questions/14967647/ (continues on next line)
            // encode-decode-image-with-base64-breaks-image (2013-04-21)
            function _binStringToArrayBuffer(bin) {
                var length = bin.length;
                var buf = new ArrayBuffer(length);
                var arr = new Uint8Array(buf);
                for (var i = 0; i < length; i++) {
                    arr[i] = bin.charCodeAt(i);
                }
                return buf;
            }

            //
            // Blobs are not supported in all versions of IndexedDB, notably
            // Chrome <37 and Android <5. In those versions, storing a blob will throw.
            //
            // Various other blob bugs exist in Chrome v37-42 (inclusive).
            // Detecting them is expensive and confusing to users, and Chrome 37-42
            // is at very low usage worldwide, so we do a hacky userAgent check instead.
            //
            // content-type bug: https://code.google.com/p/chromium/issues/detail?id=408120
            // 404 bug: https://code.google.com/p/chromium/issues/detail?id=447916
            // FileReader bug: https://code.google.com/p/chromium/issues/detail?id=447836
            //
            // Code borrowed from PouchDB. See:
            // https://github.com/pouchdb/pouchdb/blob/master/packages/node_modules/pouchdb-adapter-idb/src/blobSupport.js
            //
            function _checkBlobSupportWithoutCaching(idb) {
                return new Promise$1(function (resolve) {
                    var txn = idb.transaction(DETECT_BLOB_SUPPORT_STORE, READ_WRITE);
                    var blob = createBlob(['']);
                    txn.objectStore(DETECT_BLOB_SUPPORT_STORE).put(blob, 'key');

                    txn.onabort = function (e) {
                        // If the transaction aborts now its due to not being able to
                        // write to the database, likely due to the disk being full
                        e.preventDefault();
                        e.stopPropagation();
                        resolve(false);
                    }
                        ;

                    txn.oncomplete = function () {
                        var matchedChrome = navigator.userAgent.match(/Chrome\/(\d+)/);
                        var matchedEdge = navigator.userAgent.match(/Edge\//);
                        // MS Edge pretends to be Chrome 42:
                        // https://msdn.microsoft.com/en-us/library/hh869301%28v=vs.85%29.aspx
                        resolve(matchedEdge || !matchedChrome || parseInt(matchedChrome[1], 10) >= 43);
                    }
                        ;
                }
                )["catch"](function () {
                    return false;
                    // error, so assume unsupported
                });
            }

            function _checkBlobSupport(idb) {
                if (typeof supportsBlobs === 'boolean') {
                    return Promise$1.resolve(supportsBlobs);
                }
                return _checkBlobSupportWithoutCaching(idb).then(function (value) {
                    supportsBlobs = value;
                    return supportsBlobs;
                });
            }

            function _deferReadiness(dbInfo) {
                var dbContext = dbContexts[dbInfo.name];

                // Create a deferred object representing the current database operation.
                var deferredOperation = {};

                deferredOperation.promise = new Promise$1(function (resolve, reject) {
                    deferredOperation.resolve = resolve;
                    deferredOperation.reject = reject;
                }
                );

                // Enqueue the deferred operation.
                dbContext.deferredOperations.push(deferredOperation);

                // Chain its promise to the database readiness.
                if (!dbContext.dbReady) {
                    dbContext.dbReady = deferredOperation.promise;
                } else {
                    dbContext.dbReady = dbContext.dbReady.then(function () {
                        return deferredOperation.promise;
                    });
                }
            }

            function _advanceReadiness(dbInfo) {
                var dbContext = dbContexts[dbInfo.name];

                // Dequeue a deferred operation.
                var deferredOperation = dbContext.deferredOperations.pop();

                // Resolve its promise (which is part of the database readiness
                // chain of promises).
                if (deferredOperation) {
                    deferredOperation.resolve();
                    return deferredOperation.promise;
                }
            }

            function _rejectReadiness(dbInfo, err) {
                var dbContext = dbContexts[dbInfo.name];

                // Dequeue a deferred operation.
                var deferredOperation = dbContext.deferredOperations.pop();

                // Reject its promise (which is part of the database readiness
                // chain of promises).
                if (deferredOperation) {
                    deferredOperation.reject(err);
                    return deferredOperation.promise;
                }
            }

            function _getConnection(dbInfo, upgradeNeeded) {
                return new Promise$1(function (resolve, reject) {
                    dbContexts[dbInfo.name] = dbContexts[dbInfo.name] || createDbContext();

                    if (dbInfo.db) {
                        if (upgradeNeeded) {
                            _deferReadiness(dbInfo);
                            dbInfo.db.close();
                        } else {
                            return resolve(dbInfo.db);
                        }
                    }

                    var dbArgs = [dbInfo.name];

                    if (upgradeNeeded) {
                        dbArgs.push(dbInfo.version);
                    }

                    var openreq = idb.open.apply(idb, dbArgs);

                    if (upgradeNeeded) {
                        openreq.onupgradeneeded = function (e) {
                            var db = openreq.result;
                            try {
                                db.createObjectStore(dbInfo.storeName);
                                if (e.oldVersion <= 1) {
                                    // Added when support for blob shims was added
                                    db.createObjectStore(DETECT_BLOB_SUPPORT_STORE);
                                }
                            } catch (ex) {
                                if (ex.name === 'ConstraintError') {
                                    console.warn('The database "' + dbInfo.name + '"' + ' has been upgraded from version ' + e.oldVersion + ' to version ' + e.newVersion + ', but the storage "' + dbInfo.storeName + '" already exists.');
                                } else {
                                    throw ex;
                                }
                            }
                        }
                            ;
                    }

                    openreq.onerror = function (e) {
                        e.preventDefault();
                        reject(openreq.error);
                    }
                        ;

                    openreq.onsuccess = function () {
                        resolve(openreq.result);
                        _advanceReadiness(dbInfo);
                    }
                        ;
                }
                );
            }

            function _getOriginalConnection(dbInfo) {
                return _getConnection(dbInfo, false);
            }

            function _getUpgradedConnection(dbInfo) {
                return _getConnection(dbInfo, true);
            }

            function _isUpgradeNeeded(dbInfo, defaultVersion) {
                if (!dbInfo.db) {
                    return true;
                }

                var isNewStore = !dbInfo.db.objectStoreNames.contains(dbInfo.storeName);
                var isDowngrade = dbInfo.version < dbInfo.db.version;
                var isUpgrade = dbInfo.version > dbInfo.db.version;

                if (isDowngrade) {
                    // If the version is not the default one
                    // then warn for impossible downgrade.
                    if (dbInfo.version !== defaultVersion) {
                        console.warn('The database "' + dbInfo.name + '"' + " can't be downgraded from version " + dbInfo.db.version + ' to version ' + dbInfo.version + '.');
                    }
                    // Align the versions to prevent errors.
                    dbInfo.version = dbInfo.db.version;
                }

                if (isUpgrade || isNewStore) {
                    // If the store is new then increment the version (if needed).
                    // This will trigger an "upgradeneeded" event which is required
                    // for creating a store.
                    if (isNewStore) {
                        var incVersion = dbInfo.db.version + 1;
                        if (incVersion > dbInfo.version) {
                            dbInfo.version = incVersion;
                        }
                    }

                    return true;
                }

                return false;
            }

            // encode a blob for indexeddb engines that don't support blobs
            function _encodeBlob(blob) {
                return new Promise$1(function (resolve, reject) {
                    var reader = new FileReader();
                    reader.onerror = reject;
                    reader.onloadend = function (e) {
                        var base64 = btoa(e.target.result || '');
                        resolve({
                            __local_forage_encoded_blob: true,
                            data: base64,
                            type: blob.type
                        });
                    }
                        ;
                    reader.readAsBinaryString(blob);
                }
                );
            }

            // decode an encoded blob
            function _decodeBlob(encodedBlob) {
                var arrayBuff = _binStringToArrayBuffer(atob(encodedBlob.data));
                return createBlob([arrayBuff], {
                    type: encodedBlob.type
                });
            }

            // is this one of our fancy encoded blobs?
            function _isEncodedBlob(value) {
                return value && value.__local_forage_encoded_blob;
            }

            // Specialize the default `ready()` function by making it dependent
            // on the current database operations. Thus, the driver will be actually
            // ready when it's been initialized (default) *and* there are no pending
            // operations on the database (initiated by some other instances).
            function _fullyReady(callback) {
                var self = this;

                var promise = self._initReady().then(function () {
                    var dbContext = dbContexts[self._dbInfo.name];

                    if (dbContext && dbContext.dbReady) {
                        return dbContext.dbReady;
                    }
                });

                executeTwoCallbacks(promise, callback, callback);
                return promise;
            }

            // Try to establish a new db connection to replace the
            // current one which is broken (i.e. experiencing
            // InvalidStateError while creating a transaction).
            function _tryReconnect(dbInfo) {
                _deferReadiness(dbInfo);

                var dbContext = dbContexts[dbInfo.name];
                var forages = dbContext.forages;

                for (var i = 0; i < forages.length; i++) {
                    var forage = forages[i];
                    if (forage._dbInfo.db) {
                        forage._dbInfo.db.close();
                        forage._dbInfo.db = null;
                    }
                }
                dbInfo.db = null;

                return _getOriginalConnection(dbInfo).then(function (db) {
                    dbInfo.db = db;
                    if (_isUpgradeNeeded(dbInfo)) {
                        // Reopen the database for upgrading.
                        return _getUpgradedConnection(dbInfo);
                    }
                    return db;
                }).then(function (db) {
                    // store the latest db reference
                    // in case the db was upgraded
                    dbInfo.db = dbContext.db = db;
                    for (var i = 0; i < forages.length; i++) {
                        forages[i]._dbInfo.db = db;
                    }
                })["catch"](function (err) {
                    _rejectReadiness(dbInfo, err);
                    throw err;
                });
            }

            // FF doesn't like Promises (micro-tasks) and IDDB store operations,
            // so we have to do it with callbacks
            function createTransaction(dbInfo, mode, callback, retries) {
                if (retries === undefined) {
                    retries = 1;
                }

                try {
                    var tx = dbInfo.db.transaction(dbInfo.storeName, mode);
                    callback(null, tx);
                } catch (err) {
                    if (retries > 0 && (!dbInfo.db || err.name === 'InvalidStateError' || err.name === 'NotFoundError')) {
                        return Promise$1.resolve().then(function () {
                            if (!dbInfo.db || err.name === 'NotFoundError' && !dbInfo.db.objectStoreNames.contains(dbInfo.storeName) && dbInfo.version <= dbInfo.db.version) {
                                // increase the db version, to create the new ObjectStore
                                if (dbInfo.db) {
                                    dbInfo.version = dbInfo.db.version + 1;
                                }
                                // Reopen the database for upgrading.
                                return _getUpgradedConnection(dbInfo);
                            }
                        }).then(function () {
                            return _tryReconnect(dbInfo).then(function () {
                                createTransaction(dbInfo, mode, callback, retries - 1);
                            });
                        })["catch"](callback);
                    }

                    callback(err);
                }
            }

            function createDbContext() {
                return {
                    // Running localForages sharing a database.
                    forages: [],
                    // Shared database.
                    db: null,
                    // Database readiness (promise).
                    dbReady: null,
                    // Deferred operations on the database.
                    deferredOperations: []
                };
            }

            // Open the IndexedDB database (automatically creates one if one didn't
            // previously exist), using any options set in the config.
            function _initStorage(options) {
                var self = this;
                var dbInfo = {
                    db: null
                };

                if (options) {
                    for (var i in options) {
                        dbInfo[i] = options[i];
                    }
                }

                // Get the current context of the database;
                var dbContext = dbContexts[dbInfo.name];

                // ...or create a new context.
                if (!dbContext) {
                    dbContext = createDbContext();
                    // Register the new context in the global container.
                    dbContexts[dbInfo.name] = dbContext;
                }

                // Register itself as a running localForage in the current context.
                dbContext.forages.push(self);

                // Replace the default `ready()` function with the specialized one.
                if (!self._initReady) {
                    self._initReady = self.ready;
                    self.ready = _fullyReady;
                }

                // Create an array of initialization states of the related localForages.
                var initPromises = [];

                function ignoreErrors() {
                    // Don't handle errors here,
                    // just makes sure related localForages aren't pending.
                    return Promise$1.resolve();
                }

                for (var j = 0; j < dbContext.forages.length; j++) {
                    var forage = dbContext.forages[j];
                    if (forage !== self) {
                        // Don't wait for itself...
                        initPromises.push(forage._initReady()["catch"](ignoreErrors));
                    }
                }

                // Take a snapshot of the related localForages.
                var forages = dbContext.forages.slice(0);

                // Initialize the connection process only when
                // all the related localForages aren't pending.
                return Promise$1.all(initPromises).then(function () {
                    dbInfo.db = dbContext.db;
                    // Get the connection or open a new one without upgrade.
                    return _getOriginalConnection(dbInfo);
                }).then(function (db) {
                    dbInfo.db = db;
                    if (_isUpgradeNeeded(dbInfo, self._defaultConfig.version)) {
                        // Reopen the database for upgrading.
                        return _getUpgradedConnection(dbInfo);
                    }
                    return db;
                }).then(function (db) {
                    dbInfo.db = dbContext.db = db;
                    self._dbInfo = dbInfo;
                    // Share the final connection amongst related localForages.
                    for (var k = 0; k < forages.length; k++) {
                        var forage = forages[k];
                        if (forage !== self) {
                            // Self is already up-to-date.
                            forage._dbInfo.db = dbInfo.db;
                            forage._dbInfo.version = dbInfo.version;
                        }
                    }
                });
            }

            function getItem(key, callback) {
                var self = this;

                key = normalizeKey(key);

                var promise = new Promise$1(function (resolve, reject) {
                    self.ready().then(function () {
                        createTransaction(self._dbInfo, READ_ONLY, function (err, transaction) {
                            if (err) {
                                return reject(err);
                            }

                            try {
                                var store = transaction.objectStore(self._dbInfo.storeName);
                                var req = store.get(key);

                                req.onsuccess = function () {
                                    var value = req.result;
                                    if (value === undefined) {
                                        value = null;
                                    }
                                    if (_isEncodedBlob(value)) {
                                        value = _decodeBlob(value);
                                    }
                                    resolve(value);
                                }
                                    ;

                                req.onerror = function () {
                                    reject(req.error);
                                }
                                    ;
                            } catch (e) {
                                reject(e);
                            }
                        });
                    })["catch"](reject);
                }
                );

                executeCallback(promise, callback);
                return promise;
            }

            // Iterate over all items stored in database.
            function iterate(iterator, callback) {
                var self = this;

                var promise = new Promise$1(function (resolve, reject) {
                    self.ready().then(function () {
                        createTransaction(self._dbInfo, READ_ONLY, function (err, transaction) {
                            if (err) {
                                return reject(err);
                            }

                            try {
                                var store = transaction.objectStore(self._dbInfo.storeName);
                                var req = store.openCursor();
                                var iterationNumber = 1;

                                req.onsuccess = function () {
                                    var cursor = req.result;

                                    if (cursor) {
                                        var value = cursor.value;
                                        if (_isEncodedBlob(value)) {
                                            value = _decodeBlob(value);
                                        }
                                        var result = iterator(value, cursor.key, iterationNumber++);

                                        // when the iterator callback returns any
                                        // (non-`undefined`) value, then we stop
                                        // the iteration immediately
                                        if (result !== void 0) {
                                            resolve(result);
                                        } else {
                                            cursor["continue"]();
                                        }
                                    } else {
                                        resolve();
                                    }
                                }
                                    ;

                                req.onerror = function () {
                                    reject(req.error);
                                }
                                    ;
                            } catch (e) {
                                reject(e);
                            }
                        });
                    })["catch"](reject);
                }
                );

                executeCallback(promise, callback);

                return promise;
            }

            function setItem(key, value, callback) {
                var self = this;

                key = normalizeKey(key);

                var promise = new Promise$1(function (resolve, reject) {
                    var dbInfo;
                    self.ready().then(function () {
                        dbInfo = self._dbInfo;
                        if (toString.call(value) === '[object Blob]') {
                            return _checkBlobSupport(dbInfo.db).then(function (blobSupport) {
                                if (blobSupport) {
                                    return value;
                                }
                                return _encodeBlob(value);
                            });
                        }
                        return value;
                    }).then(function (value) {
                        createTransaction(self._dbInfo, READ_WRITE, function (err, transaction) {
                            if (err) {
                                return reject(err);
                            }

                            try {
                                var store = transaction.objectStore(self._dbInfo.storeName);

                                // The reason we don't _save_ null is because IE 10 does
                                // not support saving the `null` type in IndexedDB. How
                                // ironic, given the bug below!
                                // See: https://github.com/mozilla/localForage/issues/161
                                if (value === null) {
                                    value = undefined;
                                }

                                var req = store.put(value, key);

                                transaction.oncomplete = function () {
                                    // Cast to undefined so the value passed to
                                    // callback/promise is the same as what one would get out
                                    // of `getItem()` later. This leads to some weirdness
                                    // (setItem('foo', undefined) will return `null`), but
                                    // it's not my fault localStorage is our baseline and that
                                    // it's weird.
                                    if (value === undefined) {
                                        value = null;
                                    }

                                    resolve(value);
                                }
                                    ;
                                transaction.onabort = transaction.onerror = function () {
                                    var err = req.error ? req.error : req.transaction.error;
                                    reject(err);
                                }
                                    ;
                            } catch (e) {
                                reject(e);
                            }
                        });
                    })["catch"](reject);
                }
                );

                executeCallback(promise, callback);
                return promise;
            }

            function removeItem(key, callback) {
                var self = this;

                key = normalizeKey(key);

                var promise = new Promise$1(function (resolve, reject) {
                    self.ready().then(function () {
                        createTransaction(self._dbInfo, READ_WRITE, function (err, transaction) {
                            if (err) {
                                return reject(err);
                            }

                            try {
                                var store = transaction.objectStore(self._dbInfo.storeName);
                                // We use a Grunt task to make this safe for IE and some
                                // versions of Android (including those used by Cordova).
                                // Normally IE won't like `.delete()` and will insist on
                                // using `['delete']()`, but we have a build step that
                                // fixes this for us now.
                                var req = store["delete"](key);
                                transaction.oncomplete = function () {
                                    resolve();
                                }
                                    ;

                                transaction.onerror = function () {
                                    reject(req.error);
                                }
                                    ;

                                // The request will be also be aborted if we've exceeded our storage
                                // space.
                                transaction.onabort = function () {
                                    var err = req.error ? req.error : req.transaction.error;
                                    reject(err);
                                }
                                    ;
                            } catch (e) {
                                reject(e);
                            }
                        });
                    })["catch"](reject);
                }
                );

                executeCallback(promise, callback);
                return promise;
            }

            function clear(callback) {
                var self = this;

                var promise = new Promise$1(function (resolve, reject) {
                    self.ready().then(function () {
                        createTransaction(self._dbInfo, READ_WRITE, function (err, transaction) {
                            if (err) {
                                return reject(err);
                            }

                            try {
                                var store = transaction.objectStore(self._dbInfo.storeName);
                                var req = store.clear();

                                transaction.oncomplete = function () {
                                    resolve();
                                }
                                    ;

                                transaction.onabort = transaction.onerror = function () {
                                    var err = req.error ? req.error : req.transaction.error;
                                    reject(err);
                                }
                                    ;
                            } catch (e) {
                                reject(e);
                            }
                        });
                    })["catch"](reject);
                }
                );

                executeCallback(promise, callback);
                return promise;
            }

            function length(callback) {
                var self = this;

                var promise = new Promise$1(function (resolve, reject) {
                    self.ready().then(function () {
                        createTransaction(self._dbInfo, READ_ONLY, function (err, transaction) {
                            if (err) {
                                return reject(err);
                            }

                            try {
                                var store = transaction.objectStore(self._dbInfo.storeName);
                                var req = store.count();

                                req.onsuccess = function () {
                                    resolve(req.result);
                                }
                                    ;

                                req.onerror = function () {
                                    reject(req.error);
                                }
                                    ;
                            } catch (e) {
                                reject(e);
                            }
                        });
                    })["catch"](reject);
                }
                );

                executeCallback(promise, callback);
                return promise;
            }

            function key(n, callback) {
                var self = this;

                var promise = new Promise$1(function (resolve, reject) {
                    if (n < 0) {
                        resolve(null);

                        return;
                    }

                    self.ready().then(function () {
                        createTransaction(self._dbInfo, READ_ONLY, function (err, transaction) {
                            if (err) {
                                return reject(err);
                            }

                            try {
                                var store = transaction.objectStore(self._dbInfo.storeName);
                                var advanced = false;
                                var req = store.openKeyCursor();

                                req.onsuccess = function () {
                                    var cursor = req.result;
                                    if (!cursor) {
                                        // this means there weren't enough keys
                                        resolve(null);

                                        return;
                                    }

                                    if (n === 0) {
                                        // We have the first key, return it if that's what they
                                        // wanted.
                                        resolve(cursor.key);
                                    } else {
                                        if (!advanced) {
                                            // Otherwise, ask the cursor to skip ahead n
                                            // records.
                                            advanced = true;
                                            cursor.advance(n);
                                        } else {
                                            // When we get here, we've got the nth key.
                                            resolve(cursor.key);
                                        }
                                    }
                                }
                                    ;

                                req.onerror = function () {
                                    reject(req.error);
                                }
                                    ;
                            } catch (e) {
                                reject(e);
                            }
                        });
                    })["catch"](reject);
                }
                );

                executeCallback(promise, callback);
                return promise;
            }

            function keys(callback) {
                var self = this;

                var promise = new Promise$1(function (resolve, reject) {
                    self.ready().then(function () {
                        createTransaction(self._dbInfo, READ_ONLY, function (err, transaction) {
                            if (err) {
                                return reject(err);
                            }

                            try {
                                var store = transaction.objectStore(self._dbInfo.storeName);
                                var req = store.openKeyCursor();
                                var keys = [];

                                req.onsuccess = function () {
                                    var cursor = req.result;

                                    if (!cursor) {
                                        resolve(keys);
                                        return;
                                    }

                                    keys.push(cursor.key);
                                    cursor["continue"]();
                                }
                                    ;

                                req.onerror = function () {
                                    reject(req.error);
                                }
                                    ;
                            } catch (e) {
                                reject(e);
                            }
                        });
                    })["catch"](reject);
                }
                );

                executeCallback(promise, callback);
                return promise;
            }

            function dropInstance(options, callback) {
                callback = getCallback.apply(this, arguments);

                var currentConfig = this.config();
                options = typeof options !== 'function' && options || {};
                if (!options.name) {
                    options.name = options.name || currentConfig.name;
                    options.storeName = options.storeName || currentConfig.storeName;
                }

                var self = this;
                var promise;
                if (!options.name) {
                    promise = Promise$1.reject('Invalid arguments');
                } else {
                    var isCurrentDb = options.name === currentConfig.name && self._dbInfo.db;

                    var dbPromise = isCurrentDb ? Promise$1.resolve(self._dbInfo.db) : _getOriginalConnection(options).then(function (db) {
                        var dbContext = dbContexts[options.name];
                        var forages = dbContext.forages;
                        dbContext.db = db;
                        for (var i = 0; i < forages.length; i++) {
                            forages[i]._dbInfo.db = db;
                        }
                        return db;
                    });

                    if (!options.storeName) {
                        promise = dbPromise.then(function (db) {
                            _deferReadiness(options);

                            var dbContext = dbContexts[options.name];
                            var forages = dbContext.forages;

                            db.close();
                            for (var i = 0; i < forages.length; i++) {
                                var forage = forages[i];
                                forage._dbInfo.db = null;
                            }

                            var dropDBPromise = new Promise$1(function (resolve, reject) {
                                var req = idb.deleteDatabase(options.name);

                                req.onerror = req.onblocked = function (err) {
                                    var db = req.result;
                                    if (db) {
                                        db.close();
                                    }
                                    reject(err);
                                }
                                    ;

                                req.onsuccess = function () {
                                    var db = req.result;
                                    if (db) {
                                        db.close();
                                    }
                                    resolve(db);
                                }
                                    ;
                            }
                            );

                            return dropDBPromise.then(function (db) {
                                dbContext.db = db;
                                for (var i = 0; i < forages.length; i++) {
                                    var _forage = forages[i];
                                    _advanceReadiness(_forage._dbInfo);
                                }
                            })["catch"](function (err) {
                                (_rejectReadiness(options, err) || Promise$1.resolve())["catch"](function () { });
                                throw err;
                            });
                        });
                    } else {
                        promise = dbPromise.then(function (db) {
                            if (!db.objectStoreNames.contains(options.storeName)) {
                                return;
                            }

                            var newVersion = db.version + 1;

                            _deferReadiness(options);

                            var dbContext = dbContexts[options.name];
                            var forages = dbContext.forages;

                            db.close();
                            for (var i = 0; i < forages.length; i++) {
                                var forage = forages[i];
                                forage._dbInfo.db = null;
                                forage._dbInfo.version = newVersion;
                            }

                            var dropObjectPromise = new Promise$1(function (resolve, reject) {
                                var req = idb.open(options.name, newVersion);

                                req.onerror = function (err) {
                                    var db = req.result;
                                    db.close();
                                    reject(err);
                                }
                                    ;

                                req.onupgradeneeded = function () {
                                    var db = req.result;
                                    db.deleteObjectStore(options.storeName);
                                }
                                    ;

                                req.onsuccess = function () {
                                    var db = req.result;
                                    db.close();
                                    resolve(db);
                                }
                                    ;
                            }
                            );

                            return dropObjectPromise.then(function (db) {
                                dbContext.db = db;
                                for (var j = 0; j < forages.length; j++) {
                                    var _forage2 = forages[j];
                                    _forage2._dbInfo.db = db;
                                    _advanceReadiness(_forage2._dbInfo);
                                }
                            })["catch"](function (err) {
                                (_rejectReadiness(options, err) || Promise$1.resolve())["catch"](function () { });
                                throw err;
                            });
                        });
                    }
                }

                executeCallback(promise, callback);
                return promise;
            }

            var asyncStorage = {
                _driver: 'asyncStorage',
                _initStorage: _initStorage,
                _support: isIndexedDBValid(),
                iterate: iterate,
                getItem: getItem,
                setItem: setItem,
                removeItem: removeItem,
                clear: clear,
                length: length,
                key: key,
                keys: keys,
                dropInstance: dropInstance
            };

            function isWebSQLValid() {
                return typeof openDatabase === 'function';
            }

            // Sadly, the best way to save binary data in WebSQL/localStorage is serializing
            // it to Base64, so this is how we store it to prevent very strange errors with less
            // verbose ways of binary <-> string data storage.
            var BASE_CHARS = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';

            var BLOB_TYPE_PREFIX = '~~local_forage_type~';
            var BLOB_TYPE_PREFIX_REGEX = /^~~local_forage_type~([^~]+)~/;

            var SERIALIZED_MARKER = '__lfsc__:';
            var SERIALIZED_MARKER_LENGTH = SERIALIZED_MARKER.length;

            // OMG the serializations!
            var TYPE_ARRAYBUFFER = 'arbf';
            var TYPE_BLOB = 'blob';
            var TYPE_INT8ARRAY = 'si08';
            var TYPE_UINT8ARRAY = 'ui08';
            var TYPE_UINT8CLAMPEDARRAY = 'uic8';
            var TYPE_INT16ARRAY = 'si16';
            var TYPE_INT32ARRAY = 'si32';
            var TYPE_UINT16ARRAY = 'ur16';
            var TYPE_UINT32ARRAY = 'ui32';
            var TYPE_FLOAT32ARRAY = 'fl32';
            var TYPE_FLOAT64ARRAY = 'fl64';
            var TYPE_SERIALIZED_MARKER_LENGTH = SERIALIZED_MARKER_LENGTH + TYPE_ARRAYBUFFER.length;

            var toString$1 = Object.prototype.toString;

            function stringToBuffer(serializedString) {
                // Fill the string into a ArrayBuffer.
                var bufferLength = serializedString.length * 0.75;
                var len = serializedString.length;
                var i;
                var p = 0;
                var encoded1, encoded2, encoded3, encoded4;

                if (serializedString[serializedString.length - 1] === '=') {
                    bufferLength--;
                    if (serializedString[serializedString.length - 2] === '=') {
                        bufferLength--;
                    }
                }

                var buffer = new ArrayBuffer(bufferLength);
                var bytes = new Uint8Array(buffer);

                for (i = 0; i < len; i += 4) {
                    encoded1 = BASE_CHARS.indexOf(serializedString[i]);
                    encoded2 = BASE_CHARS.indexOf(serializedString[i + 1]);
                    encoded3 = BASE_CHARS.indexOf(serializedString[i + 2]);
                    encoded4 = BASE_CHARS.indexOf(serializedString[i + 3]);

                    /*jslint bitwise: true */
                    bytes[p++] = encoded1 << 2 | encoded2 >> 4;
                    bytes[p++] = (encoded2 & 15) << 4 | encoded3 >> 2;
                    bytes[p++] = (encoded3 & 3) << 6 | encoded4 & 63;
                }
                return buffer;
            }

            // Converts a buffer to a string to store, serialized, in the backend
            // storage library.
            function bufferToString(buffer) {
                // base64-arraybuffer
                var bytes = new Uint8Array(buffer);
                var base64String = '';
                var i;

                for (i = 0; i < bytes.length; i += 3) {
                    /*jslint bitwise: true */
                    base64String += BASE_CHARS[bytes[i] >> 2];
                    base64String += BASE_CHARS[(bytes[i] & 3) << 4 | bytes[i + 1] >> 4];
                    base64String += BASE_CHARS[(bytes[i + 1] & 15) << 2 | bytes[i + 2] >> 6];
                    base64String += BASE_CHARS[bytes[i + 2] & 63];
                }

                if (bytes.length % 3 === 2) {
                    base64String = base64String.substring(0, base64String.length - 1) + '=';
                } else if (bytes.length % 3 === 1) {
                    base64String = base64String.substring(0, base64String.length - 2) + '==';
                }

                return base64String;
            }

            // Serialize a value, afterwards executing a callback (which usually
            // instructs the `setItem()` callback/promise to be executed). This is how
            // we store binary data with localStorage.
            function serialize(value, callback) {
                var valueType = '';
                if (value) {
                    valueType = toString$1.call(value);
                }

                // Cannot use `value instanceof ArrayBuffer` or such here, as these
                // checks fail when running the tests using casper.js...
                //
                // TODO: See why those tests fail and use a better solution.
                if (value && (valueType === '[object ArrayBuffer]' || value.buffer && toString$1.call(value.buffer) === '[object ArrayBuffer]')) {
                    // Convert binary arrays to a string and prefix the string with
                    // a special marker.
                    var buffer;
                    var marker = SERIALIZED_MARKER;

                    if (value instanceof ArrayBuffer) {
                        buffer = value;
                        marker += TYPE_ARRAYBUFFER;
                    } else {
                        buffer = value.buffer;

                        if (valueType === '[object Int8Array]') {
                            marker += TYPE_INT8ARRAY;
                        } else if (valueType === '[object Uint8Array]') {
                            marker += TYPE_UINT8ARRAY;
                        } else if (valueType === '[object Uint8ClampedArray]') {
                            marker += TYPE_UINT8CLAMPEDARRAY;
                        } else if (valueType === '[object Int16Array]') {
                            marker += TYPE_INT16ARRAY;
                        } else if (valueType === '[object Uint16Array]') {
                            marker += TYPE_UINT16ARRAY;
                        } else if (valueType === '[object Int32Array]') {
                            marker += TYPE_INT32ARRAY;
                        } else if (valueType === '[object Uint32Array]') {
                            marker += TYPE_UINT32ARRAY;
                        } else if (valueType === '[object Float32Array]') {
                            marker += TYPE_FLOAT32ARRAY;
                        } else if (valueType === '[object Float64Array]') {
                            marker += TYPE_FLOAT64ARRAY;
                        } else {
                            callback(new Error('Failed to get type for BinaryArray'));
                        }
                    }

                    callback(marker + bufferToString(buffer));
                } else if (valueType === '[object Blob]') {
                    // Conver the blob to a binaryArray and then to a string.
                    var fileReader = new FileReader();

                    fileReader.onload = function () {
                        // Backwards-compatible prefix for the blob type.
                        var str = BLOB_TYPE_PREFIX + value.type + '~' + bufferToString(this.result);

                        callback(SERIALIZED_MARKER + TYPE_BLOB + str);
                    }
                        ;

                    fileReader.readAsArrayBuffer(value);
                } else {
                    try {
                        callback(JSON.stringify(value));
                    } catch (e) {
                        console.error("Couldn't convert value into a JSON string: ", value);

                        callback(null, e);
                    }
                }
            }

            // Deserialize data we've inserted into a value column/field. We place
            // special markers into our strings to mark them as encoded; this isn't
            // as nice as a meta field, but it's the only sane thing we can do whilst
            // keeping localStorage support intact.
            //
            // Oftentimes this will just deserialize JSON content, but if we have a
            // special marker (SERIALIZED_MARKER, defined above), we will extract
            // some kind of arraybuffer/binary data/typed array out of the string.
            function deserialize(value) {
                // If we haven't marked this string as being specially serialized (i.e.
                // something other than serialized JSON), we can just return it and be
                // done with it.
                if (value.substring(0, SERIALIZED_MARKER_LENGTH) !== SERIALIZED_MARKER) {
                    return JSON.parse(value);
                }

                // The following code deals with deserializing some kind of Blob or
                // TypedArray. First we separate out the type of data we're dealing
                // with from the data itself.
                var serializedString = value.substring(TYPE_SERIALIZED_MARKER_LENGTH);
                var type = value.substring(SERIALIZED_MARKER_LENGTH, TYPE_SERIALIZED_MARKER_LENGTH);

                var blobType;
                // Backwards-compatible blob type serialization strategy.
                // DBs created with older versions of localForage will simply not have the blob type.
                if (type === TYPE_BLOB && BLOB_TYPE_PREFIX_REGEX.test(serializedString)) {
                    var matcher = serializedString.match(BLOB_TYPE_PREFIX_REGEX);
                    blobType = matcher[1];
                    serializedString = serializedString.substring(matcher[0].length);
                }
                var buffer = stringToBuffer(serializedString);

                // Return the right type based on the code/type set during
                // serialization.
                switch (type) {
                    case TYPE_ARRAYBUFFER:
                        return buffer;
                    case TYPE_BLOB:
                        return createBlob([buffer], {
                            type: blobType
                        });
                    case TYPE_INT8ARRAY:
                        return new Int8Array(buffer);
                    case TYPE_UINT8ARRAY:
                        return new Uint8Array(buffer);
                    case TYPE_UINT8CLAMPEDARRAY:
                        return new Uint8ClampedArray(buffer);
                    case TYPE_INT16ARRAY:
                        return new Int16Array(buffer);
                    case TYPE_UINT16ARRAY:
                        return new Uint16Array(buffer);
                    case TYPE_INT32ARRAY:
                        return new Int32Array(buffer);
                    case TYPE_UINT32ARRAY:
                        return new Uint32Array(buffer);
                    case TYPE_FLOAT32ARRAY:
                        return new Float32Array(buffer);
                    case TYPE_FLOAT64ARRAY:
                        return new Float64Array(buffer);
                    default:
                        throw new Error('Unkown type: ' + type);
                }
            }

            var localforageSerializer = {
                serialize: serialize,
                deserialize: deserialize,
                stringToBuffer: stringToBuffer,
                bufferToString: bufferToString
            };

            /*
             * Includes code from:
             *
             * base64-arraybuffer
             * https://github.com/niklasvh/base64-arraybuffer
             *
             * Copyright (c) 2012 Niklas von Hertzen
             * Licensed under the MIT license.
             */

            function createDbTable(t, dbInfo, callback, errorCallback) {
                t.executeSql('CREATE TABLE IF NOT EXISTS ' + dbInfo.storeName + ' ' + '(id INTEGER PRIMARY KEY, key unique, value)', [], callback, errorCallback);
            }

            // Open the WebSQL database (automatically creates one if one didn't
            // previously exist), using any options set in the config.
            function _initStorage$1(options) {
                var self = this;
                var dbInfo = {
                    db: null
                };

                if (options) {
                    for (var i in options) {
                        dbInfo[i] = typeof options[i] !== 'string' ? options[i].toString() : options[i];
                    }
                }

                var dbInfoPromise = new Promise$1(function (resolve, reject) {
                    // Open the database; the openDatabase API will automatically
                    // create it for us if it doesn't exist.
                    try {
                        dbInfo.db = openDatabase(dbInfo.name, String(dbInfo.version), dbInfo.description, dbInfo.size);
                    } catch (e) {
                        return reject(e);
                    }

                    // Create our key/value table if it doesn't exist.
                    dbInfo.db.transaction(function (t) {
                        createDbTable(t, dbInfo, function () {
                            self._dbInfo = dbInfo;
                            resolve();
                        }, function (t, error) {
                            reject(error);
                        });
                    }, reject);
                }
                );

                dbInfo.serializer = localforageSerializer;
                return dbInfoPromise;
            }

            function tryExecuteSql(t, dbInfo, sqlStatement, args, callback, errorCallback) {
                t.executeSql(sqlStatement, args, callback, function (t, error) {
                    if (error.code === error.SYNTAX_ERR) {
                        t.executeSql('SELECT name FROM sqlite_master ' + "WHERE type='table' AND name = ?", [dbInfo.storeName], function (t, results) {
                            if (!results.rows.length) {
                                // if the table is missing (was deleted)
                                // re-create it table and retry
                                createDbTable(t, dbInfo, function () {
                                    t.executeSql(sqlStatement, args, callback, errorCallback);
                                }, errorCallback);
                            } else {
                                errorCallback(t, error);
                            }
                        }, errorCallback);
                    } else {
                        errorCallback(t, error);
                    }
                }, errorCallback);
            }

            function getItem$1(key, callback) {
                var self = this;

                key = normalizeKey(key);

                var promise = new Promise$1(function (resolve, reject) {
                    self.ready().then(function () {
                        var dbInfo = self._dbInfo;
                        dbInfo.db.transaction(function (t) {
                            tryExecuteSql(t, dbInfo, 'SELECT * FROM ' + dbInfo.storeName + ' WHERE key = ? LIMIT 1', [key], function (t, results) {
                                var result = results.rows.length ? results.rows.item(0).value : null;

                                // Check to see if this is serialized content we need to
                                // unpack.
                                if (result) {
                                    result = dbInfo.serializer.deserialize(result);
                                }

                                resolve(result);
                            }, function (t, error) {
                                reject(error);
                            });
                        });
                    })["catch"](reject);
                }
                );

                executeCallback(promise, callback);
                return promise;
            }

            function iterate$1(iterator, callback) {
                var self = this;

                var promise = new Promise$1(function (resolve, reject) {
                    self.ready().then(function () {
                        var dbInfo = self._dbInfo;

                        dbInfo.db.transaction(function (t) {
                            tryExecuteSql(t, dbInfo, 'SELECT * FROM ' + dbInfo.storeName, [], function (t, results) {
                                var rows = results.rows;
                                var length = rows.length;

                                for (var i = 0; i < length; i++) {
                                    var item = rows.item(i);
                                    var result = item.value;

                                    // Check to see if this is serialized content
                                    // we need to unpack.
                                    if (result) {
                                        result = dbInfo.serializer.deserialize(result);
                                    }

                                    result = iterator(result, item.key, i + 1);

                                    // void(0) prevents problems with redefinition
                                    // of `undefined`.
                                    if (result !== void 0) {
                                        resolve(result);
                                        return;
                                    }
                                }

                                resolve();
                            }, function (t, error) {
                                reject(error);
                            });
                        });
                    })["catch"](reject);
                }
                );

                executeCallback(promise, callback);
                return promise;
            }

            function _setItem(key, value, callback, retriesLeft) {
                var self = this;

                key = normalizeKey(key);

                var promise = new Promise$1(function (resolve, reject) {
                    self.ready().then(function () {
                        // The localStorage API doesn't return undefined values in an
                        // "expected" way, so undefined is always cast to null in all
                        // drivers. See: https://github.com/mozilla/localForage/pull/42
                        if (value === undefined) {
                            value = null;
                        }

                        // Save the original value to pass to the callback.
                        var originalValue = value;

                        var dbInfo = self._dbInfo;
                        dbInfo.serializer.serialize(value, function (value, error) {
                            if (error) {
                                reject(error);
                            } else {
                                dbInfo.db.transaction(function (t) {
                                    tryExecuteSql(t, dbInfo, 'INSERT OR REPLACE INTO ' + dbInfo.storeName + ' ' + '(key, value) VALUES (?, ?)', [key, value], function () {
                                        resolve(originalValue);
                                    }, function (t, error) {
                                        reject(error);
                                    });
                                }, function (sqlError) {
                                    // The transaction failed; check
                                    // to see if it's a quota error.
                                    if (sqlError.code === sqlError.QUOTA_ERR) {
                                        // We reject the callback outright for now, but
                                        // it's worth trying to re-run the transaction.
                                        // Even if the user accepts the prompt to use
                                        // more storage on Safari, this error will
                                        // be called.
                                        //
                                        // Try to re-run the transaction.
                                        if (retriesLeft > 0) {
                                            resolve(_setItem.apply(self, [key, originalValue, callback, retriesLeft - 1]));
                                            return;
                                        }
                                        reject(sqlError);
                                    }
                                });
                            }
                        });
                    })["catch"](reject);
                }
                );

                executeCallback(promise, callback);
                return promise;
            }

            function setItem$1(key, value, callback) {
                return _setItem.apply(this, [key, value, callback, 1]);
            }

            function removeItem$1(key, callback) {
                var self = this;

                key = normalizeKey(key);

                var promise = new Promise$1(function (resolve, reject) {
                    self.ready().then(function () {
                        var dbInfo = self._dbInfo;
                        dbInfo.db.transaction(function (t) {
                            tryExecuteSql(t, dbInfo, 'DELETE FROM ' + dbInfo.storeName + ' WHERE key = ?', [key], function () {
                                resolve();
                            }, function (t, error) {
                                reject(error);
                            });
                        });
                    })["catch"](reject);
                }
                );

                executeCallback(promise, callback);
                return promise;
            }

            // Deletes every item in the table.
            // TODO: Find out if this resets the AUTO_INCREMENT number.
            function clear$1(callback) {
                var self = this;

                var promise = new Promise$1(function (resolve, reject) {
                    self.ready().then(function () {
                        var dbInfo = self._dbInfo;
                        dbInfo.db.transaction(function (t) {
                            tryExecuteSql(t, dbInfo, 'DELETE FROM ' + dbInfo.storeName, [], function () {
                                resolve();
                            }, function (t, error) {
                                reject(error);
                            });
                        });
                    })["catch"](reject);
                }
                );

                executeCallback(promise, callback);
                return promise;
            }

            // Does a simple `COUNT(key)` to get the number of items stored in
            // localForage.
            function length$1(callback) {
                var self = this;

                var promise = new Promise$1(function (resolve, reject) {
                    self.ready().then(function () {
                        var dbInfo = self._dbInfo;
                        dbInfo.db.transaction(function (t) {
                            // Ahhh, SQL makes this one soooooo easy.
                            tryExecuteSql(t, dbInfo, 'SELECT COUNT(key) as c FROM ' + dbInfo.storeName, [], function (t, results) {
                                var result = results.rows.item(0).c;
                                resolve(result);
                            }, function (t, error) {
                                reject(error);
                            });
                        });
                    })["catch"](reject);
                }
                );

                executeCallback(promise, callback);
                return promise;
            }

            // Return the key located at key index X; essentially gets the key from a
            // `WHERE id = ?`. This is the most efficient way I can think to implement
            // this rarely-used (in my experience) part of the API, but it can seem
            // inconsistent, because we do `INSERT OR REPLACE INTO` on `setItem()`, so
            // the ID of each key will change every time it's updated. Perhaps a stored
            // procedure for the `setItem()` SQL would solve this problem?
            // TODO: Don't change ID on `setItem()`.
            function key$1(n, callback) {
                var self = this;

                var promise = new Promise$1(function (resolve, reject) {
                    self.ready().then(function () {
                        var dbInfo = self._dbInfo;
                        dbInfo.db.transaction(function (t) {
                            tryExecuteSql(t, dbInfo, 'SELECT key FROM ' + dbInfo.storeName + ' WHERE id = ? LIMIT 1', [n + 1], function (t, results) {
                                var result = results.rows.length ? results.rows.item(0).key : null;
                                resolve(result);
                            }, function (t, error) {
                                reject(error);
                            });
                        });
                    })["catch"](reject);
                }
                );

                executeCallback(promise, callback);
                return promise;
            }

            function keys$1(callback) {
                var self = this;

                var promise = new Promise$1(function (resolve, reject) {
                    self.ready().then(function () {
                        var dbInfo = self._dbInfo;
                        dbInfo.db.transaction(function (t) {
                            tryExecuteSql(t, dbInfo, 'SELECT key FROM ' + dbInfo.storeName, [], function (t, results) {
                                var keys = [];

                                for (var i = 0; i < results.rows.length; i++) {
                                    keys.push(results.rows.item(i).key);
                                }

                                resolve(keys);
                            }, function (t, error) {
                                reject(error);
                            });
                        });
                    })["catch"](reject);
                }
                );

                executeCallback(promise, callback);
                return promise;
            }

            // https://www.w3.org/TR/webdatabase/#databases
            // > There is no way to enumerate or delete the databases available for an origin from this API.
            function getAllStoreNames(db) {
                return new Promise$1(function (resolve, reject) {
                    db.transaction(function (t) {
                        t.executeSql('SELECT name FROM sqlite_master ' + "WHERE type='table' AND name <> '__WebKitDatabaseInfoTable__'", [], function (t, results) {
                            var storeNames = [];

                            for (var i = 0; i < results.rows.length; i++) {
                                storeNames.push(results.rows.item(i).name);
                            }

                            resolve({
                                db: db,
                                storeNames: storeNames
                            });
                        }, function (t, error) {
                            reject(error);
                        });
                    }, function (sqlError) {
                        reject(sqlError);
                    });
                }
                );
            }

            function dropInstance$1(options, callback) {
                callback = getCallback.apply(this, arguments);

                var currentConfig = this.config();
                options = typeof options !== 'function' && options || {};
                if (!options.name) {
                    options.name = options.name || currentConfig.name;
                    options.storeName = options.storeName || currentConfig.storeName;
                }

                var self = this;
                var promise;
                if (!options.name) {
                    promise = Promise$1.reject('Invalid arguments');
                } else {
                    promise = new Promise$1(function (resolve) {
                        var db;
                        if (options.name === currentConfig.name) {
                            // use the db reference of the current instance
                            db = self._dbInfo.db;
                        } else {
                            db = openDatabase(options.name, '', '', 0);
                        }

                        if (!options.storeName) {
                            // drop all database tables
                            resolve(getAllStoreNames(db));
                        } else {
                            resolve({
                                db: db,
                                storeNames: [options.storeName]
                            });
                        }
                    }
                    ).then(function (operationInfo) {
                        return new Promise$1(function (resolve, reject) {
                            operationInfo.db.transaction(function (t) {
                                function dropTable(storeName) {
                                    return new Promise$1(function (resolve, reject) {
                                        t.executeSql('DROP TABLE IF EXISTS ' + storeName, [], function () {
                                            resolve();
                                        }, function (t, error) {
                                            reject(error);
                                        });
                                    }
                                    );
                                }

                                var operations = [];
                                for (var i = 0, len = operationInfo.storeNames.length; i < len; i++) {
                                    operations.push(dropTable(operationInfo.storeNames[i]));
                                }

                                Promise$1.all(operations).then(function () {
                                    resolve();
                                })["catch"](function (e) {
                                    reject(e);
                                });
                            }, function (sqlError) {
                                reject(sqlError);
                            });
                        }
                        );
                    });
                }

                executeCallback(promise, callback);
                return promise;
            }

            var webSQLStorage = {
                _driver: 'webSQLStorage',
                _initStorage: _initStorage$1,
                _support: isWebSQLValid(),
                iterate: iterate$1,
                getItem: getItem$1,
                setItem: setItem$1,
                removeItem: removeItem$1,
                clear: clear$1,
                length: length$1,
                key: key$1,
                keys: keys$1,
                dropInstance: dropInstance$1
            };

            function isLocalStorageValid() {
                try {
                    return typeof localStorage !== 'undefined' && 'setItem' in localStorage && // in IE8 typeof localStorage.setItem === 'object'
                        !!localStorage.setItem;
                } catch (e) {
                    return false;
                }
            }

            function _getKeyPrefix(options, defaultConfig) {
                var keyPrefix = options.name + '/';

                if (options.storeName !== defaultConfig.storeName) {
                    keyPrefix += options.storeName + '/';
                }
                return keyPrefix;
            }

            // Check if localStorage throws when saving an item
            function checkIfLocalStorageThrows() {
                var localStorageTestKey = '_localforage_support_test';

                try {
                    localStorage.setItem(localStorageTestKey, true);
                    localStorage.removeItem(localStorageTestKey);

                    return false;
                } catch (e) {
                    return true;
                }
            }

            // Check if localStorage is usable and allows to save an item
            // This method checks if localStorage is usable in Safari Private Browsing
            // mode, or in any other case where the available quota for localStorage
            // is 0 and there wasn't any saved items yet.
            function _isLocalStorageUsable() {
                return !checkIfLocalStorageThrows() || localStorage.length > 0;
            }

            // Config the localStorage backend, using options set in the config.
            function _initStorage$2(options) {
                var self = this;
                var dbInfo = {};
                if (options) {
                    for (var i in options) {
                        dbInfo[i] = options[i];
                    }
                }

                dbInfo.keyPrefix = _getKeyPrefix(options, self._defaultConfig);

                if (!_isLocalStorageUsable()) {
                    return Promise$1.reject();
                }

                self._dbInfo = dbInfo;
                dbInfo.serializer = localforageSerializer;

                return Promise$1.resolve();
            }

            // Remove all keys from the datastore, effectively destroying all data in
            // the app's key/value store!
            function clear$2(callback) {
                var self = this;
                var promise = self.ready().then(function () {
                    var keyPrefix = self._dbInfo.keyPrefix;

                    for (var i = localStorage.length - 1; i >= 0; i--) {
                        var key = localStorage.key(i);

                        if (key.indexOf(keyPrefix) === 0) {
                            localStorage.removeItem(key);
                        }
                    }
                });

                executeCallback(promise, callback);
                return promise;
            }

            // Retrieve an item from the store. Unlike the original async_storage
            // library in Gaia, we don't modify return values at all. If a key's value
            // is `undefined`, we pass that value to the callback function.
            function getItem$2(key, callback) {
                var self = this;

                key = normalizeKey(key);

                var promise = self.ready().then(function () {
                    var dbInfo = self._dbInfo;
                    var result = localStorage.getItem(dbInfo.keyPrefix + key);

                    // If a result was found, parse it from the serialized
                    // string into a JS object. If result isn't truthy, the key
                    // is likely undefined and we'll pass it straight to the
                    // callback.
                    if (result) {
                        result = dbInfo.serializer.deserialize(result);
                    }

                    return result;
                });

                executeCallback(promise, callback);
                return promise;
            }

            // Iterate over all items in the store.
            function iterate$2(iterator, callback) {
                var self = this;

                var promise = self.ready().then(function () {
                    var dbInfo = self._dbInfo;
                    var keyPrefix = dbInfo.keyPrefix;
                    var keyPrefixLength = keyPrefix.length;
                    var length = localStorage.length;

                    // We use a dedicated iterator instead of the `i` variable below
                    // so other keys we fetch in localStorage aren't counted in
                    // the `iterationNumber` argument passed to the `iterate()`
                    // callback.
                    //
                    // See: github.com/mozilla/localForage/pull/435#discussion_r38061530
                    var iterationNumber = 1;

                    for (var i = 0; i < length; i++) {
                        var key = localStorage.key(i);
                        if (key.indexOf(keyPrefix) !== 0) {
                            continue;
                        }
                        var value = localStorage.getItem(key);

                        // If a result was found, parse it from the serialized
                        // string into a JS object. If result isn't truthy, the
                        // key is likely undefined and we'll pass it straight
                        // to the iterator.
                        if (value) {
                            value = dbInfo.serializer.deserialize(value);
                        }

                        value = iterator(value, key.substring(keyPrefixLength), iterationNumber++);

                        if (value !== void 0) {
                            return value;
                        }
                    }
                });

                executeCallback(promise, callback);
                return promise;
            }

            // Same as localStorage's key() method, except takes a callback.
            function key$2(n, callback) {
                var self = this;
                var promise = self.ready().then(function () {
                    var dbInfo = self._dbInfo;
                    var result;
                    try {
                        result = localStorage.key(n);
                    } catch (error) {
                        result = null;
                    }

                    // Remove the prefix from the key, if a key is found.
                    if (result) {
                        result = result.substring(dbInfo.keyPrefix.length);
                    }

                    return result;
                });

                executeCallback(promise, callback);
                return promise;
            }

            function keys$2(callback) {
                var self = this;
                var promise = self.ready().then(function () {
                    var dbInfo = self._dbInfo;
                    var length = localStorage.length;
                    var keys = [];

                    for (var i = 0; i < length; i++) {
                        var itemKey = localStorage.key(i);
                        if (itemKey.indexOf(dbInfo.keyPrefix) === 0) {
                            keys.push(itemKey.substring(dbInfo.keyPrefix.length));
                        }
                    }

                    return keys;
                });

                executeCallback(promise, callback);
                return promise;
            }

            // Supply the number of keys in the datastore to the callback function.
            function length$2(callback) {
                var self = this;
                var promise = self.keys().then(function (keys) {
                    return keys.length;
                });

                executeCallback(promise, callback);
                return promise;
            }

            // Remove an item from the store, nice and simple.
            function removeItem$2(key, callback) {
                var self = this;

                key = normalizeKey(key);

                var promise = self.ready().then(function () {
                    var dbInfo = self._dbInfo;
                    localStorage.removeItem(dbInfo.keyPrefix + key);
                });

                executeCallback(promise, callback);
                return promise;
            }

            // Set a key's value and run an optional callback once the value is set.
            // Unlike Gaia's implementation, the callback function is passed the value,
            // in case you want to operate on that value only after you're sure it
            // saved, or something like that.
            function setItem$2(key, value, callback) {
                var self = this;

                key = normalizeKey(key);

                var promise = self.ready().then(function () {
                    // Convert undefined values to null.
                    // https://github.com/mozilla/localForage/pull/42
                    if (value === undefined) {
                        value = null;
                    }

                    // Save the original value to pass to the callback.
                    var originalValue = value;

                    return new Promise$1(function (resolve, reject) {
                        var dbInfo = self._dbInfo;
                        dbInfo.serializer.serialize(value, function (value, error) {
                            if (error) {
                                reject(error);
                            } else {
                                try {
                                    localStorage.setItem(dbInfo.keyPrefix + key, value);
                                    resolve(originalValue);
                                } catch (e) {
                                    // localStorage capacity exceeded.
                                    // TODO: Make this a specific error/event.
                                    if (e.name === 'QuotaExceededError' || e.name === 'NS_ERROR_DOM_QUOTA_REACHED') {
                                        reject(e);
                                    }
                                    reject(e);
                                }
                            }
                        });
                    }
                    );
                });

                executeCallback(promise, callback);
                return promise;
            }

            function dropInstance$2(options, callback) {
                callback = getCallback.apply(this, arguments);

                options = typeof options !== 'function' && options || {};
                if (!options.name) {
                    var currentConfig = this.config();
                    options.name = options.name || currentConfig.name;
                    options.storeName = options.storeName || currentConfig.storeName;
                }

                var self = this;
                var promise;
                if (!options.name) {
                    promise = Promise$1.reject('Invalid arguments');
                } else {
                    promise = new Promise$1(function (resolve) {
                        if (!options.storeName) {
                            resolve(options.name + '/');
                        } else {
                            resolve(_getKeyPrefix(options, self._defaultConfig));
                        }
                    }
                    ).then(function (keyPrefix) {
                        for (var i = localStorage.length - 1; i >= 0; i--) {
                            var key = localStorage.key(i);

                            if (key.indexOf(keyPrefix) === 0) {
                                localStorage.removeItem(key);
                            }
                        }
                    });
                }

                executeCallback(promise, callback);
                return promise;
            }

            var localStorageWrapper = {
                _driver: 'localStorageWrapper',
                _initStorage: _initStorage$2,
                _support: isLocalStorageValid(),
                iterate: iterate$2,
                getItem: getItem$2,
                setItem: setItem$2,
                removeItem: removeItem$2,
                clear: clear$2,
                length: length$2,
                key: key$2,
                keys: keys$2,
                dropInstance: dropInstance$2
            };

            var sameValue = function sameValue(x, y) {
                return x === y || typeof x === 'number' && typeof y === 'number' && isNaN(x) && isNaN(y);
            };

            var includes = function includes(array, searchElement) {
                var len = array.length;
                var i = 0;
                while (i < len) {
                    if (sameValue(array[i], searchElement)) {
                        return true;
                    }
                    i++;
                }

                return false;
            };

            var isArray = Array.isArray || function (arg) {
                return Object.prototype.toString.call(arg) === '[object Array]';
            }
                ;

            // Drivers are stored here when `defineDriver()` is called.
            // They are shared across all instances of localForage.
            var DefinedDrivers = {};

            var DriverSupport = {};

            var DefaultDrivers = {
                INDEXEDDB: asyncStorage,
                WEBSQL: webSQLStorage,
                LOCALSTORAGE: localStorageWrapper
            };

            var DefaultDriverOrder = [DefaultDrivers.INDEXEDDB._driver, DefaultDrivers.WEBSQL._driver, DefaultDrivers.LOCALSTORAGE._driver];

            var OptionalDriverMethods = ['dropInstance'];

            var LibraryMethods = ['clear', 'getItem', 'iterate', 'key', 'keys', 'length', 'removeItem', 'setItem'].concat(OptionalDriverMethods);

            var DefaultConfig = {
                description: '',
                driver: DefaultDriverOrder.slice(),
                name: 'localforage',
                // Default DB size is _JUST UNDER_ 5MB, as it's the highest size
                // we can use without a prompt.
                size: 4980736,
                storeName: 'keyvaluepairs',
                version: 1.0
            };

            function callWhenReady(localForageInstance, libraryMethod) {
                localForageInstance[libraryMethod] = function () {
                    var _args = arguments;
                    return localForageInstance.ready().then(function () {
                        return localForageInstance[libraryMethod].apply(localForageInstance, _args);
                    });
                }
                    ;
            }

            function extend() {
                for (var i = 1; i < arguments.length; i++) {
                    var arg = arguments[i];

                    if (arg) {
                        for (var _key in arg) {
                            if (arg.hasOwnProperty(_key)) {
                                if (isArray(arg[_key])) {
                                    arguments[0][_key] = arg[_key].slice();
                                } else {
                                    arguments[0][_key] = arg[_key];
                                }
                            }
                        }
                    }
                }

                return arguments[0];
            }

            var LocalForage = function () {
                function LocalForage(options) {
                    _classCallCheck(this, LocalForage);

                    for (var driverTypeKey in DefaultDrivers) {
                        if (DefaultDrivers.hasOwnProperty(driverTypeKey)) {
                            var driver = DefaultDrivers[driverTypeKey];
                            var driverName = driver._driver;
                            this[driverTypeKey] = driverName;

                            if (!DefinedDrivers[driverName]) {
                                // we don't need to wait for the promise,
                                // since the default drivers can be defined
                                // in a blocking manner
                                this.defineDriver(driver);
                            }
                        }
                    }

                    this._defaultConfig = extend({}, DefaultConfig);
                    this._config = extend({}, this._defaultConfig, options);
                    this._driverSet = null;
                    this._initDriver = null;
                    this._ready = false;
                    this._dbInfo = null;

                    this._wrapLibraryMethodsWithReady();
                    this.setDriver(this._config.driver)["catch"](function () { });
                }

                // Set any config values for localForage; can be called anytime before
                // the first API call (e.g. `getItem`, `setItem`).
                // We loop through options so we don't overwrite existing config
                // values.

                LocalForage.prototype.config = function config(options) {
                    // If the options argument is an object, we use it to set values.
                    // Otherwise, we return either a specified config value or all
                    // config values.
                    if ((typeof options === 'undefined' ? 'undefined' : _typeof(options)) === 'object') {
                        // If localforage is ready and fully initialized, we can't set
                        // any new configuration values. Instead, we return an error.
                        if (this._ready) {
                            return new Error("Can't call config() after localforage " + 'has been used.');
                        }

                        for (var i in options) {
                            if (i === 'storeName') {
                                options[i] = options[i].replace(/\W/g, '_');
                            }

                            if (i === 'version' && typeof options[i] !== 'number') {
                                return new Error('Database version must be a number.');
                            }

                            this._config[i] = options[i];
                        }

                        // after all config options are set and
                        // the driver option is used, try setting it
                        if ('driver' in options && options.driver) {
                            return this.setDriver(this._config.driver);
                        }

                        return true;
                    } else if (typeof options === 'string') {
                        return this._config[options];
                    } else {
                        return this._config;
                    }
                }
                    ;

                // Used to define a custom driver, shared across all instances of
                // localForage.

                LocalForage.prototype.defineDriver = function defineDriver(driverObject, callback, errorCallback) {
                    var promise = new Promise$1(function (resolve, reject) {
                        try {
                            var driverName = driverObject._driver;
                            var complianceError = new Error('Custom driver not compliant; see ' + 'https://mozilla.github.io/localForage/#definedriver');

                            // A driver name should be defined and not overlap with the
                            // library-defined, default drivers.
                            if (!driverObject._driver) {
                                reject(complianceError);
                                return;
                            }

                            var driverMethods = LibraryMethods.concat('_initStorage');
                            for (var i = 0, len = driverMethods.length; i < len; i++) {
                                var driverMethodName = driverMethods[i];

                                // when the property is there,
                                // it should be a method even when optional
                                var isRequired = !includes(OptionalDriverMethods, driverMethodName);
                                if ((isRequired || driverObject[driverMethodName]) && typeof driverObject[driverMethodName] !== 'function') {
                                    reject(complianceError);
                                    return;
                                }
                            }

                            var configureMissingMethods = function configureMissingMethods() {
                                var methodNotImplementedFactory = function methodNotImplementedFactory(methodName) {
                                    return function () {
                                        var error = new Error('Method ' + methodName + ' is not implemented by the current driver');
                                        var promise = Promise$1.reject(error);
                                        executeCallback(promise, arguments[arguments.length - 1]);
                                        return promise;
                                    }
                                        ;
                                };

                                for (var _i = 0, _len = OptionalDriverMethods.length; _i < _len; _i++) {
                                    var optionalDriverMethod = OptionalDriverMethods[_i];
                                    if (!driverObject[optionalDriverMethod]) {
                                        driverObject[optionalDriverMethod] = methodNotImplementedFactory(optionalDriverMethod);
                                    }
                                }
                            };

                            configureMissingMethods();

                            var setDriverSupport = function setDriverSupport(support) {
                                if (DefinedDrivers[driverName]) {
                                    console.info('Redefining LocalForage driver: ' + driverName);
                                }
                                DefinedDrivers[driverName] = driverObject;
                                DriverSupport[driverName] = support;
                                // don't use a then, so that we can define
                                // drivers that have simple _support methods
                                // in a blocking manner
                                resolve();
                            };

                            if ('_support' in driverObject) {
                                if (driverObject._support && typeof driverObject._support === 'function') {
                                    driverObject._support().then(setDriverSupport, reject);
                                } else {
                                    setDriverSupport(!!driverObject._support);
                                }
                            } else {
                                setDriverSupport(true);
                            }
                        } catch (e) {
                            reject(e);
                        }
                    }
                    );

                    executeTwoCallbacks(promise, callback, errorCallback);
                    return promise;
                }
                    ;

                LocalForage.prototype.driver = function driver() {
                    return this._driver || null;
                }
                    ;

                LocalForage.prototype.getDriver = function getDriver(driverName, callback, errorCallback) {
                    var getDriverPromise = DefinedDrivers[driverName] ? Promise$1.resolve(DefinedDrivers[driverName]) : Promise$1.reject(new Error('Driver not found.'));

                    executeTwoCallbacks(getDriverPromise, callback, errorCallback);
                    return getDriverPromise;
                }
                    ;

                LocalForage.prototype.getSerializer = function getSerializer(callback) {
                    var serializerPromise = Promise$1.resolve(localforageSerializer);
                    executeTwoCallbacks(serializerPromise, callback);
                    return serializerPromise;
                }
                    ;

                LocalForage.prototype.ready = function ready(callback) {
                    var self = this;

                    var promise = self._driverSet.then(function () {
                        if (self._ready === null) {
                            self._ready = self._initDriver();
                        }

                        return self._ready;
                    });

                    executeTwoCallbacks(promise, callback, callback);
                    return promise;
                }
                    ;

                LocalForage.prototype.setDriver = function setDriver(drivers, callback, errorCallback) {
                    var self = this;

                    if (!isArray(drivers)) {
                        drivers = [drivers];
                    }

                    var supportedDrivers = this._getSupportedDrivers(drivers);

                    function setDriverToConfig() {
                        self._config.driver = self.driver();
                    }

                    function extendSelfWithDriver(driver) {
                        self._extend(driver);
                        setDriverToConfig();

                        self._ready = self._initStorage(self._config);
                        return self._ready;
                    }

                    function initDriver(supportedDrivers) {
                        return function () {
                            var currentDriverIndex = 0;

                            function driverPromiseLoop() {
                                while (currentDriverIndex < supportedDrivers.length) {
                                    var driverName = supportedDrivers[currentDriverIndex];
                                    currentDriverIndex++;

                                    self._dbInfo = null;
                                    self._ready = null;

                                    return self.getDriver(driverName).then(extendSelfWithDriver)["catch"](driverPromiseLoop);
                                }

                                setDriverToConfig();
                                var error = new Error('No available storage method found.');
                                self._driverSet = Promise$1.reject(error);
                                return self._driverSet;
                            }

                            return driverPromiseLoop();
                        }
                            ;
                    }

                    // There might be a driver initialization in progress
                    // so wait for it to finish in order to avoid a possible
                    // race condition to set _dbInfo
                    var oldDriverSetDone = this._driverSet !== null ? this._driverSet["catch"](function () {
                        return Promise$1.resolve();
                    }) : Promise$1.resolve();

                    this._driverSet = oldDriverSetDone.then(function () {
                        var driverName = supportedDrivers[0];
                        self._dbInfo = null;
                        self._ready = null;

                        return self.getDriver(driverName).then(function (driver) {
                            self._driver = driver._driver;
                            setDriverToConfig();
                            self._wrapLibraryMethodsWithReady();
                            self._initDriver = initDriver(supportedDrivers);
                        });
                    })["catch"](function () {
                        setDriverToConfig();
                        var error = new Error('No available storage method found.');
                        self._driverSet = Promise$1.reject(error);
                        return self._driverSet;
                    });

                    executeTwoCallbacks(this._driverSet, callback, errorCallback);
                    return this._driverSet;
                }
                    ;

                LocalForage.prototype.supports = function supports(driverName) {
                    return !!DriverSupport[driverName];
                }
                    ;

                LocalForage.prototype._extend = function _extend(libraryMethodsAndProperties) {
                    extend(this, libraryMethodsAndProperties);
                }
                    ;

                LocalForage.prototype._getSupportedDrivers = function _getSupportedDrivers(drivers) {
                    var supportedDrivers = [];
                    for (var i = 0, len = drivers.length; i < len; i++) {
                        var driverName = drivers[i];
                        if (this.supports(driverName)) {
                            supportedDrivers.push(driverName);
                        }
                    }
                    return supportedDrivers;
                }
                    ;

                LocalForage.prototype._wrapLibraryMethodsWithReady = function _wrapLibraryMethodsWithReady() {
                    // Add a stub for each driver API method that delays the call to the
                    // corresponding driver method until localForage is ready. These stubs
                    // will be replaced by the driver methods as soon as the driver is
                    // loaded, so there is no performance impact.
                    for (var i = 0, len = LibraryMethods.length; i < len; i++) {
                        callWhenReady(this, LibraryMethods[i]);
                    }
                }
                    ;

                LocalForage.prototype.createInstance = function createInstance(options) {
                    return new LocalForage(options);
                }
                    ;

                return LocalForage;
            }();

            // The actual localForage object that we expose as a module or via a
            // global. It's extended by pulling in one of our other libraries.

            var localforage_js = new LocalForage();

            module.exports = localforage_js;

        }
            , {
            "3": 3
        }]
    }, {}, [4])(4)
});
